1. Field of the Invention
The present invention relates to battery mounting structures for vehicles, with which a battery can be mounted in a vehicle such as an electric vehicle or an electric hybrid vehicle.
2. Description of the Related Art
In a vehicle such as an electric vehicle or an engine/electric hybrid vehicle, a battery used as a travel power source is conventionally mounted in the vehicle, housed in a battery box serving as a protective container.
For example, Japanese Unexamined Patent Application Publication No. 2006-335243 describes a power supply device for a vehicle in which a battery box that includes a battery cover and houses a plurality of battery modules is connected to a side frame of a vehicle body via a support frame extending in a left-right direction.
Further, to ensure that a center of gravity of the vehicle is low and secure sufficient space in a cabin, the battery box is preferably mounted in an under-floor portion. In this case, however, measures must be taken to ensure that the battery is not drenched with water churned up by a vehicle wheel, water sprayed by a high-pressure car-washing machine during car washing, and so on.
For example, Japanese Unexamined Patent Application Publication No. 2009-35126 describes a battery box structure having vertically separated housing spaces, in which a battery that is vulnerable to drenching is housed in an upper housing space and accessories are housed in a lower housing space.
The structure described in Japanese Unexamined Patent Application Publication No. 2009-35126 is designed to be mounted on a frame side of a hybrid electric truck, and since the battery is disposed on the upper side, the center of gravity of the vehicle is high. Moreover, the height of the battery box is increased, and it is therefore difficult to secure cabin space. Hence, the structure cannot easily be disposed in an under-floor portion of a passenger car, for example.